Power distribution system control and monitoring

ABSTRACT

In one example embodiment, a power control system includes one or more stages, a plurality of primary busbars operatively coupled to the one or more stages, and an intelligent controller operatively coupled to the one or more stages. Each of the one or more stages is configured to generate a lead current when coupled in parallel to a power distribution system, and at least one of the one or more stages comprises a notch filter and a power tank circuit. Each of the plurality of primary busbars is configured to carry one phase of a multiple phase power signal. The controller is configured to determine when to switch each of the one or more stages one and off, to count a number of times each stage is switched on, and to track one or more electrical parameters of the power distribution system, power control system, or both.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 13/346,552, filed Jan. 9, 2012, entitled “POWERDISTRIBUTION SYSTEM AND MONITORING” which is a divisional application ofU.S. application Ser. No. 12/272,731, filed Nov. 17, 2008, entitled“POWER DISTRIBUTION SYSTEM CONTROL AND MONITORING,” now U.S. Pat. No.8,093,871, which claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 60/988,732, entitled “POWER DISTRIBUTION SYSTEMCONTROL AND MONITORING,” filed Nov. 16, 2007, the contents of each ofthe foregoing applications are incorporated herein, in their entirety,by this reference.

BACKGROUND

1. Field of the Invention

The present invention generally relates to methods, systems, and devicesfor use in power distribution systems. More specifically, some exampleembodiments of the invention relate to a power control system forproviding power factor correction in a power distribution system.

2. The Relevant Technology

In multiple phase power distribution systems, such as three-phasesystems, much effort is expended in order to compensate for loads havingless than idea power factors. Ideally, the transmitted alternatingvoltage and current are always in phase. Power is transmitted mostefficiently when the alternative voltage and current are in phase.

In practice, electrical power providers have found that the loadspresented to their power distributions systems have been, in aggregate,inductive in nature rather than purely resistive. Inductive loads causethe phase of the alternating current to lag behind the phase of thealternating voltage. The measure of the degree of current lag is calledthe power factor and is expressed as the cosine of the angle θ betweenthe alternating voltage and the alternating current. Generally, thelarger the inductance of the load, the greater the lag current.

The subject matter claimed herein is not limited to embodiments thatsolve any disadvantages or that operate only in environments such asthose described above. Rather, this background is only provided toillustrate one exemplary technology area where some embodimentsdescribed herein may be practiced

BRIEF SUMMARY OF SOME EXAMPLE EMBODIMENTS

In general, example embodiments of the invention relate to power controlsystems for use in power distribution systems.

In one example embodiment, a power control system includes one or morestages, a plurality of primary busbars operatively coupled to each ofthe one or more stages, and an intelligent controller operativelycoupled to each of the one or more stages. Each of the one or morestages is configured to generate a lead current when coupled in parallelto a power distribution system, and at least one of the one or morestages comprises a notch filter and a power tank circuit. Each of theplurality of primary busbars is configured to carry one phase of amultiple phase power signal. The controller is configured to determinewhen to switch each of the one or more stages one and off, to count anumber of times each stage is switched on, and to track one or moreelectrical parameters of the power distribution system, power controlsystem, or both.

In another example embodiment, a power capacitor is provided that can beimplemented in one or more stages of a power control system. The powercapacitor includes three balanced capacitors arranged in a deltaconfiguration, three resistors, and three diodes. The deltaconfiguration includes three contact points interposed between the threebalanced capacitors. Each resistor includes two inputs and one output,each input being coupled to one of the three contact points. The threediodes are configured to allow power stored in the balanced capacitorsto be discharged from the power capacitor. Each diode includes an inputcoupled to an output of a different resistor and an output coupled toground.

These and other aspects of example embodiments of the invention willbecome more fully apparent from the following description and appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 illustrates a first example embodiment of a power control systemaccording to embodiments of the invention;

FIGS. 2 illustrates a second example embodiment of a power controlsystem according to embodiments of the invention;

FIG. 3 illustrates an example embodiment of a capacitor switchingcontactor that can be implemented in one or more stages of the powercontrol systems of FIGS. 1 and 2;

FIG. 4A illustrates an example embodiment of a power capacitor that canbe implemented in one or more stages of the power control systems ofFIGS. 1 and 2;

FIG. 4B illustrates an example embodiment of a plurality of layers thatcan be implemented in balanced capacitors of the power capacitor of FIG.4A;

FIG. 5 illustrates an example embodiment of a tuned reactor zig-zagtransformer that can be implemented in one or more stages of the powercontrol systems of FIGS. 1 and 2;

FIGS. 6A-6C illustrate an example embodiment of a controller andcomponents thereof that can be implemented in the power control systemsof FIGS. 1 and 2; and

FIGS. 7A and 7B illustrate an example embodiment of an active harmonicfilter and components thereof that can be implemented in the powercontrol systems of FIGS. 1 and 2.

DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

Embodiments of the invention relate to systems, methods, and devices foruse in power distribution systems. Embodiments of the invention includea power control system and various components for use within and by thepower control system and/or other systems, the components including acontroller, capacitor switching contactors, power capacitors, tunedreactor zig-zag transformers, and active harmonic filters.

I. Power Control System

With reference first to FIG. 1, one example power control system 100 isdepicted according to embodiments of the invention. The power controlsystem 100 in some embodiments operates to provide power factorcorrection, harmonic suppression, voltage variance suppression, and/or apower tank storage function in a multiple phase alternating current(“AC”) environment, such as a three phase power distribution system.While the power control system 100 and its components will be describedin some detail, the power control system 100 and its components areprovided by way of example only and should not be construed to limit theinvention.

The power control system 100 includes a plurality of primary busbars102A, 102B, 102C (referred to collectively herein as “primary busbars102”), one or more stages 104A to 104N (collectively referred to hereinas “stages 104”), and a controller 106. In some embodiments, the primarybusbars 102 comprise copper busbars rated for 600 amps, and each of theprimary busbars 102 is configured to carry one phase of a multiple phasepower signal. In the present example, for instance, each of the primarybusbars 102 is configured to carry one phase of a three-phase powersignal such as may be implemented in power distribution systemsthroughout the world.

The primary busbars 102 are operatively coupled to each of the one ormore stages 104 via conductive wires 108. In some embodiments, each ofthe conductive wires 108 is rated for approximately 100 amps.

The number of stages 104 in the power control system 100 can depend insome embodiments on the needs of the power distribution system in whichthe power control system 100 is implemented. For instance, the powerdistribution system 100 for a single-family dwelling may implement apower control system with a single stage 104A or only a few stages 104,whereas a power distribution system for a factory or multi-story officebuilding may implement a power control system with a greater number ofstages 104, such as up to twelve stages 104 in some embodiments.Alternately or additionally, the power control system 100 can include afixed number of stages 104 without regard to the needs of the powerdistribution system in which the power control system 100 isimplemented. Optionally, manufacturers and/or vendors of the powercontrol system 100 can provide a design allowance to add or take outstages 104 quickly and easily to upgrade or downgrade the power controlsystem 100 according to changes as may be necessary when a customergrows or reduces their power needs.

Further, the configuration of each stage 104 in a multi-stage powercontrol system 100 can be the same or different. For instance, eachstage can be configured to create a lead current to cancel out a lagcurrent in the multiple phase power signal carried by the primarybusbars 102. Alternately or additionally, one stage can be configured tosuppress a first harmonic frequency on the multiple phase power signal.Alternately or additionally, one or more other stages can be configuredto suppress one or more other harmonic frequencies on the multiple phasepower signal. Each stage configured to suppress a harmonic frequency maysuppress one of the harmonic frequencies selected from the groupconsisting of the 3^(rd), 5^(th), and 7^(th) harmonic frequencies, orother harmonic frequencies in some embodiments. One example embodimentof a stage configured to suppress a particular harmonic frequency (e.g.,stage 104A) on the multiple phase power signal will be described in moredetail below.

As disclosed in FIG. 1, stage 104A includes a multiple phase circuitbreaker 110 coupled to the busbars 102, a capacitor switching contactor112 coupled to the multiple phase circuit breaker 110, and one or morepower capacitors 114A, 114B, 114C (collectively referred to herein as“power capacitors 114”). The multiple phase circuit breaker 110,capacitor switching contactor 112 and/or power capacitors 114 can becoupled together via conductive wires 115 that may comprise wire ratedfor 100 amps in some embodiments.

The multiple phase circuit breaker 110 is configured to protect thestage 104A from current surges in the multiple phase power signalcarried by primary busbars 102 and can be rated for 100 amps in someembodiments. The power capacitors 114 are configured to provide powerfactor correction, creating a lead current to counteract a lag currentcaused when a load on the power distribution system in which the powercontrol system 100 is implemented is inductive. The capacitor switchingcontactor 112 is configured to switch the stage 104A in our out of thepower distribution system as instructed by the controller 106.

Each additional stage 104N similarly includes a multiple phase circuitbreaker 116, a capacitor switching contactor 118, and one or more powercapacitors 120A, 120B, 120C (collectively referred to herein as “powercapacitors 120”). Although each of the stages 104 is shown in FIG. 1with three power capacitors 114 or 120, each stage 104 can alternatelyinclude one or two power capacitors or more than three power capacitors.In some embodiments, the controller 106 determines how many of thestages 104 to switch in or out of the power distribution system at anygiven time, depending on, for instance, the amount of power factorcorrection desired for the power distribution system at any given time.

In some embodiments, each stage 104A-104N further includes a pluralityof secondary busbars 122, 124, respectively. The secondary busbars 122are configured to couple the power capacitors 114 together in parallel.Similarly, secondary busbars 124 are configured to couple the powercapacitors 120 together in parallel. The secondary busbars 122, 124comprise copper busbars rated at 100A in some embodiments. Alternatelyor additionally, power capacitors 114 (and 120) can be coupled togetherin parallel using busbars or conductive wire rated for more or less than100A.

At least one stage 104A further includes a tuned reactor zig-zagtransformer 126 coupled between the capacitor switching contactor 112and power capacitors 114. That is, the tuned reactor zig-zag transformer126 is configured as both a tuned reactor and a zig-zag transformer, aswill be explained in greater detail below. In its capacity as a tunedreactor, the tuned reactor zig-zag transformer 126 is configured tosuppress switching damage that would otherwise result from, e.g.,current inrush when the power capacitors 114 are switched on. In itscapacity as a zig-zag transformer, the tuned reactor zig-zag transformer126 is configured to suppress voltage and/or current variance in themultiple phase power signal.

Additionally, implementation of the tuned reactor zig-zag transformer126 in conjunction with the capacitor switching contactor 112 and powercapacitors 114 allows the stage 104A to be configured as both a notchfilter for harmonic frequency suppression of a particular harmonicfrequency, and as a power holding tank circuit to smooth out powervariations. In a multi-stage power control system, one or more of theother stages 104N can optionally include a tuned reactor zig-zagtransformer 126.

Briefly, the controller 106 is configured to, among other things,control each of the stages 104. For instance, the controller 106 isconfigured to determine when to switch each stage 104 on or off,depending on the power factor in the power distribution system at anygiven time. To that end, the controller 106 can receive data from aplurality of probes that measure, for instance, the phase differencebetween voltage and current in the multiple phase power signal carriedon the primary busbars 102. Alternately or additionally, the controller106 can be configured to count the number of times each stage isswitched on and/or off. Alternately or additionally, the controller 106can be configured to monitor each notch filter and power tank circuitformed by one or more stages 104 of the power control system 100.Alternately or additionally, the controller 106 can be configured totrack various electrical parameters for the power distribution system,such as the current, voltage, and/or AC frequency of the multiple phasepower signal and/or the power consumed by the power distribution system.Various aspects of the controller 106 will be described in greaterdetail below.

Although not shown, the power control system 100 and/or a powerdistribution system in which the power control system 100 is implementedcan optionally include one or more passive harmonic filters operativelycoupled to the power control system 100 and/or power distributionsystem. In some embodiments, passive harmonic frequencies tuned toharmonic frequencies above approximately 50 kHz can be coupled to thepower distribution system near the source of the harmonic frequencies.The passive harmonic filters can be configured to control extreme powerspikes such as may be produced by the power source and/or from eventssuch as lightning. Alternately or additionally, the passive harmonicfilters can be configured to suppress harmonic distortion at the primeharmonic frequency up to the thirty-second harmonic frequency. The oneor more passive harmonic filters are further configured to protect thepower capacitors 114 and in some embodiments can reduce each of theaforementioned harmonic frequency ranges an average of 10%.

In some embodiments, the power control system 100 is configured tohandle current needs ranging from 100 amps to 3,000 amps per phase.Although not shown, the power control system 100 can optionally includestand-off insulators to protect the primary busbars 102 and currentcarrying circuits.

In some embodiments, the power control system 100 can include a fusedstep down transformer (see FIG. 6A) to convert medium voltage power tolow voltage power in order to operate the controller 106 and a fan orother active cooling system. The controller 106 can be configured tomonitor the temperature of the power control system 100 and turn the fanor other active cooling system on and off for cooling as needed. In someembodiments, the fan or other active cooling system is configured tomove sufficient air to exceed by 300% the anticipated heat value of allinternal components of the power control system 100. Alternately oradditionally, the power control system 100 can include an air filter tofilter outside air for circulation within an enclosure in which thepower control system 100 is housed.

With additional reference briefly to FIG. 2, one embodiment of a workingpower control system 200 is disclosed that may correspond to the powercontrol system 100 of FIG. 1. The power control system 200 includes aplurality of primary busbars 202, three stages 204, and a controller206. The power control system 200 further includes a passive harmonicfilter 208. As shown, the components 202-206 are disposed within ahousing 210 that includes a door 210A. Advantageously, the components202-206 are arranged within the housing in such a way that they are allaccessible for service and/or testing at any time by simply opening thedoor 210A. In some embodiments, the volume enclosed by the housing 210is 40 cubic feet or less, allowing the power control system 200 to beplaced in relatively small spaces not allowed for by conventional powercontrol systems.

Optionally, the power control system 200 can include an on-off switch(not shown) built into the door 210A. Alternately or additionally, thepower control system 200 can include a safety switch built into the door210A that is configured to automatically turn off the power to the powercontrol system 200 when the door 210A is opened or tampered with. Thepower control system 200 can provide means for bypassing the safetyswitch if testing of the power control system 200 is desired.

As will be explained in more detail below with respect to FIGS. 7A and7B, the power control systems 100 or 200 can be implemented inconjunction with one or more active harmonic filters. Such activeharmonic filters can be configured to suppress large and extremeharmonic distortion levels. In such embodiments, the controller 106, 206can be configured to call for and monitor the activity of the one ormore active harmonic filters as separate entities or stages within thepower control systems 100, 200.

II. Capacitor Switching Contactor

With additional reference to FIG. 3, aspects of an example capacitorswitching contactor 300 will be disclosed. The capacitor switchingcontactor 300 may correspond to the capacitor switching contactors 112,118 of FIG. 1 and can be rated at 600 volts and 100 amps in someembodiments. As shown, the capacitor switching contactor 300 includes aplurality of contact point sets 302, 304, 306, a plurality of arc chutes308, 310, 312, a solenoid 314, and an insulating enclosure 316.

In some embodiments, the capacitor switching contactor 300 includes onecontact point set and arc chute for each phase of a multiple phase powersignal carried by the primary busbars 102 of FIG. 1. Each contact pointset 302, 304, 306 includes a first contact point 302A, 304A, 306A and asecond contact point 302B, 304B, 306B. The first contact points 302A,304A, 306A are configured to be coupled to the primary busbars 102 ofFIG. 1 via wires 318, 320, 322. The second contact points 302B, 304B,306B are configured to be coupled to the power capacitors 114 (eitherdirectly or indirectly via the tuned reactor zig-zag transformer 126)via wires 324, 326, 328. Alternately or additionally, the coupling ofthe first contact points 302A-306A and of the second contact points302B-306B to the primary busbars 102 and power capacitors 114 can bereversed. In some embodiments, the wires 318-328 are rated forapproximately 100 amps.

Each contact point set 302-306 is configured to open and close anelectrical connection between two or more components. As used herein, anelectrical connection between two components is “open” when there iseffectively an infinite resistance between the two components. Incontrast, an electrical connection between two components is “closed”when there is a low resistance between the two components.

For instance, contact point set 302 may be configured to open and closean electrical connection between primary busbar 102A and a terminal oneach of power capacitors 114 in FIG. 1. Similarly, contact point set 304can be configured to open and close an electrical connection betweenprimary busbar 102B and a terminal on each of power capacitors 114,while contact point set 306 can be configured to open and close anelectrical connection between primary busbar 102C and a terminal on eachof power capacitors 114.

In some embodiments, the contact point sets 302-306 comprise a hardmetal such as titanium metal that is characterized by a relatively largeresistance to offset capacitor inrush current when the contact pointsets 302-306 close the electrical connection between power capacitors114 and primary busbars 102 in FIG. 1.

As will be appreciated by those skilled in the art, when an electricalconnection is opened or closed by a contact point set, pitting and otherdamage can occur to the contact points as electrical discharge currentcan arc between the two contact points immediately before they come incontact in the case of closing the electrical connection, or immediatelyafter they break contact in the case of opening the electricalconnection. To reduce such pitting and other damage, embodiments of thecapacitor switching contactor 300 include arc chutes 308-312. Arc chutes308-312 are positioned proximate contact point sets 302-306,respectively. When the contact point sets 302-306 are opened and closed,arc chutes 308-312 are configured to receive any electrical dischargecurrent generated by opening and closing the contact point sets 302-306to prevent pitting and other damage to contact point sets 302-306. Eachof the second contact points 302B-306B is electrically coupled to acorresponding arc chute 308-312

According to some embodiments of the invention, each second contactpoint 302B-306B is mechanically coupled to solenoid 314. The solenoid314 is configured to impart forces sufficient to move second contactpoints 302B-306B away from and towards first contact points 302A-306A toopen and close the contact point sets 302-306 in response to signalsreceived from the controller 106 of FIG. 1 via control wires 314A and314B. In some embodiments, the solenoid 314 may comprise a 120 volt coilconfigured to close the second contact points 302B-306B and one or moresprings configured to open the second contact points 302B-306B, or viceversa.

The contact point sets 302-306, arc chutes 308-312, and solenoid 314 arehoused within insulating enclosure 316. In some embodiments, theinsulating enclosure 316 is configured to form an electromagneticinterference (“EMI”) shield around the components 302-314 tosubstantially prevent electromagnetic radiation (“EMR”) from entering orleaving the insulating enclosure 316. To form the EMI shield, theinsulating enclosure 316 may comprise plastic with an Aluminum thread ormesh embedded therein. Alternately or additionally, other suitablematerials can be implemented for the insulating enclosure 316. As shownin FIG. 3, the insulating enclosure 316 can be coupled to ground 330

Although not shown, the capacitor switching contactor 300 can optionallyinclude a first plurality of tuned choke coils coupled to the wires 318,320, 322, a second plurality of tuned choke coils coupled to the wires324, 326, 328, and a second plurality of contact point sets coupledbetween the first plurality of tuned choke coils and second plurality oftuned choke coils. Each of the second plurality of contact point setscan be rated for 10 amps with a nominal voltage rating of 250 volts insome embodiments and can include a contact point mechanically coupled tothe solenoid 314.

In some embodiments, immediately before closing and/or immediately afteropening the first plurality of contact point sets 302-306, the solenoid314 can be configured to close the second plurality of contact pointsets for a short time (e.g., on the order of 1/60^(th) of a second) tosuppress inrush and/or outrush current. For the brief time that thesecond plurality of contact point sets are closed and for each phase ofthe multiple phase power signal, one of the first plurality of tunedchoke coils aligns with one of the second plurality of tuned choke coilsto dampen inrush and/or outrush current as the power capacitors 114 arecoupled to or decoupled from the primary busbars 102 in FIG. 1. Thefirst and second plurality of tuned choke coils can be tuned to dampenfrequencies ranging from 40-70 cycles per second (“Hz”) in someembodiments. Whereas British power distribution systems operate at about50 Hz and North American power distribution systems operate at about 60Hz, the first and second plurality of tuned choke coils can dissipatemuch of the inrush and outrush currents and voltages typical ofswitching power capacitors. Alternately or additionally, the first andsecond plurality of tuned choke coils can be electrically protected byinsulating covers made of, for example, plastic.

Although not shown, in some embodiments the capacitor switchingcontactor 300 can include a common rail clip designation to facilitatefast connect and disconnect of the capacitor switching contactor 300 tothe power control systems 100, 200 of FIGS. 1 and 2. Alternately oradditionally, one or more of the wires 318-328 can terminate with orotherwise include wire contact points configured to couple to strandedor solid wire to electrically couple the capacitor switching contactor300 to components of the power control system 100 or 200. The strandedor solid wire can be rated at 100 amps and 600 volts in someembodiments.

III. Power Capacitors

With additional reference to FIGS. 4A and 4B, aspects of an examplepower capacitor 400 will be disclosed. The power capacitor 400 maycorrespond to one or more of the power capacitors 114, 120 of FIG. 1.Alternately or additionally, the power capacitor 400 can be implementedin environments other than the power control system 100 of FIG. 1.Alternately or additionally, the power capacitor 400 can be rated tohandle 150 amps at up to 600 volts without failure in some embodimentsand/or can be rated to operate at AC power frequencies between 45 Hz and65 Hz. As shown in FIG. 4A, the power capacitor 400 includes threebalanced capacitors 402, 404, 406, three resistors 408, 410, 412, andthree diodes 414, 416, 418.

Each of the three balanced capacitors 402-406 is balanced with theothers, insofar as each of the balanced capacitors is characterized bythe same capacitor ratings (e.g., the same kVAr ratings). Further, eachof the three balanced capacitors 402-406 can comprise a self-repairingcapacitor, as will be explained in greater detail below. Further, thethree balanced capacitors 402-406 are arranged in a delta configuration,meaning each of capacitors 402-406 is coupled to two adjacent capacitorsand three contact points 420, 422, 424 are interposed between the threecapacitor 402-406, a different contact point being disposed between eachpair of adjacent capacitors. The delta configuration of the balancedcapacitors 402-406 allows the power capacitor 400 to be implemented in anotch filter in conjunction with a tuned reactor zig-zag transformer126, if desired.

Each of the resistors 408-412 can comprise a center tap resistor thatincludes two inputs and one output. Each input of each resistor 408-412is coupled to one of the contact points 420-424. For instance, theinputs of resistor 408 are coupled to contact points 420 and 424; theinputs of resistor 410 are coupled to contact points 420 and 422; theinputs of resistor 412 are coupled to contact points 422 and 424. Eachoutput of each resistor 408-412 is coupled to one of the diodes 414-418,respectively.

Each of the diodes 414-418 can comprise a power diode. An input of eachdiode 414-418 is coupled to an output of resistor 408-412, respectively,while an output of each diode 414-418 is coupled to ground 426. When theelectrical connection between the power capacitor 400 and the primarybusbars 102 of FIG. 1 is closed, power is stored by the power capacitor400. When the electrical connection is opened, the diodes 414-418 allowcurrent to flow to ground 426, safely discharging the power capacitor400.

In some embodiments, each of the balanced capacitors 402-406 comprises aplurality of layers 430, as shown in the cross-sectional side view ofthe plurality of layers 430 in FIG. 4B. Alternately or additionally, theplurality of layers 430 can be rolled to form one or more of thebalanced capacitors 402-406. The plurality of layers 430 includes a foillayer 432 configured to store electrical charge, an insulation layer 434configured to insulate the foil layer 432, and a repairing layer 434disposed between the foil layer 432 and insulation layer 434 andconfigured to self-repair the foil layer 432 and/or insulation layer 434in the event of damage.

The foil layer 432 can comprise anodized foil in some embodiments toincrease the current failure value of the balanced capacitors 402-406.Alternately or additionally, the insulation layer 434 can comprisebiaxially-oriented polyethylene terephthalate (boPET) polyester film,also commonly known as Mylar or Melinex. The insulation layer 434 can becoated with a polycarbonate film to increase the voltage and/orfrequency resiliency of the balanced capacitors 402-406 to damage.

To prevent the balanced capacitors 402-406 from shorting out in theevent of damage, the plurality of layers 430 include repairing layer434. Generally, capacitors can short out when a hole forms in aninsulation layer and/or foil layer. To prevent shorting out, therepairing layer 436 is configured to fill any holes formed in the foillayer 432 and/or insulation layer 434. For instance, the repairing layer436 may comprise a thermoplastic that exists in solid form at the powercapacitor's 400 normal operating temperatures of about 30° C.-130° C.and that exists in liquid form at around 400° C. Upon formation of ahole in the foil layer 432 and/or insulation layer 434, and electricaldischarge current can discharge through the hole, heating a portion ofthe repairing layer 436 in the vicinity of the hole to around 400° C.The high temperature liquefies the portion of the repairing layer 436 inthe vicinity of the hole, and the liquefied portion of the repairinglayer 436 flows into the hole, extinguishes the electrical dischargecurrent, and solidifies as the temperature drops to the powercapacitor's 400 normal operating temperature.

Returning to FIG. 4A, the power capacitor 400 can further include acapacitor housing 440 that may comprise medium grade steel, such as 22gauge steel, in some embodiments. Alternately or additionally, thecapacitor housing 440 may comprise other suitable materials. Thecapacitor housing 440 is configured to prevent any faults within thecapacitor housing 440 from escaping and/or causing damage to componentsoutside the capacitor housing 440.

The capacitor housing 440 defines a cavity in which the balancedcapacitors 402-406, resistors 408-412 and diodes 414-418 are disposed.The capacitor housing 440 may comprise a rectangular or square box shapein some embodiments to facilitate stacking multiple power capacitors 400together.

Alternately or additionally, the power capacitor 400 can include a fluid442 substantially filling volume in the cavity not occupied by thebalanced capacitors 402-406, resistors 408-412 and diodes 414-418. Insome embodiments, the fluid 442 comprises refined vegetable oil,dielectric oil, FR3 dielectric oil, or the like. The fluid 442 may besubstantially non-flammable at high temperatures (e.g., above the normaloperating temperatures of the power capacitor 400) and non-reactive toover currents. Alternately or additionally, in some embodiments thefluid 442 can be configured to naturally decompose without incineration,facilitating easy and environmentally-friendly disposal.

Each of the three contact points 420-424 is coupled to a correspondingterminal disposed on the exterior of the capacitor housing 440. Theterminals on the exterior of the capacitor housing 440 can be arrangedwith sufficient space in between to prevent any voltage or powerexchange between the terminals at operating voltages up to and including600 volts in some embodiments. For instance, in some embodiments theterminals on the exterior of the capacitor housing 440 are spaced atleast an inch apart from each other.

In some embodiments of the invention, the power capacitor 400 can berated for at least 10×10³ volt-ampere reactive power (VAr), or 10 kVAr.Alternately or additionally, the power capacitor 400 can be ratedbetween 10 kVAr and 25 kVAr.

IV. Tuned Reactor Zig-Zag Transformer

With additional reference to FIG. 5, aspects of an example tuned reactorzig-zag transformer 500 will be disclosed. The tuned reactor zig-zagtransformer 500 may correspond to the tuned reactor zig-zag transformer126 of FIG. 1. As mentioned above, at least one of the stages 104 ofpower control system 100 can include a tuned reactor zig-zagtransformer, although not required in every stage 104. Alternately oradditionally, the tuned reactor zig-zag transformer 500 can beimplemented in environments other than the power control system 100 ofFIG. 1. Further, in some embodiments the tuned reactor zig-zagtransformer is configured to handle currents as high as 100 amps.

The tuned reactor zig-zag transformer 500 includes a core 502, and aplurality of wires 504, 506, 508. Each wire 504-508 is configured tocarry a different phase of the multiple phase power signal carried bythe primary busbars 102 of FIG. 1. Further, each wire 504, 506, 508includes an input 504A, 506A, 508A, and an output 504B, 506B, 508B. Withcombined reference to FIGS. 1 and 5, for example, inputs 504A, 506A and508A are configured to be coupled to, respectively, primary busbars102A, 102B and 102C via capacitor switching contactor 112, while outputs504B, 506B and 508B are configured to be coupled to power capacitors114.

The core 502 can comprise laminated iron with sufficient size to preventmagnetic saturation during operation with alternating currents ofapproximately 100 amps on wires 504-508. For instance, in someembodiments the core 502 weighs at least 70 pounds. Alternately oradditionally, the core 502 can weigh more or less than 70 pounds. Forinstance, in some embodiments the core can weight anywhere from 50-80pounds. The relatively large size of the core 502 compared to cores usedin conventional zig-zag transformers is configured to prevent magneticsaturation of the tuned reactor zig-zag transformer 500 during operationat or near 100 amps.

As shown in FIG. 5, the core 502 comprises three coupled cores 510, 512and 514. Each of the wires 504-508 includes a plurality of windingsdisposed about a portion of each of the coupled cores 510-514. Forinstance, wire 504 includes a first plurality of windings 516A, a secondplurality of windings 518A, and a third plurality of windings 520Adisposed about cores 510, 512, and 514, respectively. Wire 506 includesa first plurality of windings 516B, a second plurality of windings 518B,and a third plurality of windings 520B disposed about cores 512, 514,and 510, respectively. Wire 508 includes a first plurality of windings516C, a second plurality of windings 518C, and a third plurality ofwindings 520C disposed about cores 514, 512, and 510, respectively.

Each of the first plurality of windings 516A, 516B, 516C (collectivelyreferred to herein as “first plurality of windings 516”) can include thesame number of turns a in some embodiments. Alternately or additionally,each of the second plurality of windings 518A, 518B, 518C (collectivelyreferred to herein as “second plurality of windings 518”) and thirdplurality of windings 520A, 520B, 520C (collectively referred to hereinas “third plurality of windings 520”) can include the same number ofturns b. The number of turns a of the first plurality of windings 516can be larger than the number of turns b of the second and thirdplurality of windings 518, 520 in some embodiments. Further, each of thefirst plurality of windings 516 is wound around the coupled iron cores510-514 in one direction, while both the second plurality of windings518 and third plurality of windings 520 are wound around the couplediron cores 510-514 in the opposite direction.

In operation, the current carried by each of wires 504-508 alternates at60 cycles per second in a 60 Hz 3-phase AC environment. During eachcycle of each phase, the first plurality of windings 516 stronglymagnetizes a corresponding one of the coupled cores 510-514, while thesecond plurality of windings 518 and third plurality of windings 520weakly magnetize corresponding coupled cores 510-514. With 3 phases andan AC frequency of 60 Hz, the core 502 changes magnetic condition 180times per second in a round-robin fashion.

The high-frequency change in magnetic condition of the core 502 forcesthe tuned reactor zig-zag transformer 500 to stabilize at a commonground between the 3-phases of the power signal. More particularly,because tuned reactor zig-zag transformer 500 has an inductive reactancethat has the ability to transfer voltage between wires 504-508, theforced and rapid inductive reaction of the tuned reactor zig-zagtransformer 500 caused by the high-frequency changes in magneticcondition of the core 502 tends to resist any fluctuation in voltage andcurrent between the phases of the power signal carried by wires 504-508.Accordingly, the tuned reactor zig-zag transformer 500 is configured tosuppress voltage and current variations in the 3-phase power signal whenthe tuned reactor zig-zag transformer 500 is coupled to the primarybusbars 102 carrying a 3-phase power signal.

The number of turns a and b of the first, second, and third plurality ofwindings 516, 518, 520 and/or the size of the core 502 can be selectedin some embodiments to tune the tuned reactor zig-zag transformer 500 tosuppress a particular harmonic frequency of the multiple phase powersignal. For instance, the number of turns a and b and/or size of thecore 502 can be selected to tune the tuned reactor zig-zag transformer500 to suppress the third harmonic frequency of the multiple phase powersignal. Alternately or additionally, the tuned reactor zig-zagtransformer 500 can be tuned to suppress some other harmonic frequency,such as the fifth or seventh harmonic frequency.

According to some embodiments of the invention, the tuning of the tunedreactor zig-zag transformer 500 is approximately 1.2 degrees off aparticular harmonic frequency to create a notch filter. As used herein,a “notch filter” refers to a plurality of inter-related capacitors(e.g., power capacitors 114 of FIG. 1) coupled against inductive coils(e.g., the plurality of windings 516-520) that are tuned to thecapacitors (e.g., by selecting the appropriate number of turns a, b) toattenuate signal frequencies within a narrow range of signalfrequencies.

As already mentioned, the tuned reactor zig-zag transformer 500 can betuned to approximately 1.2 degrees off a target frequency in someembodiments to avoid creating a short circuit. In particular, if thereactance X_(inductor) of an inductive coil (e.g., plurality of windings516-520) is equal to the reactance X capacitor of a capacitor (e.g.,power capacitors 114) coupled to the inductive coil, a short circuitcondition is created:

X _(inductor) ×X _(capacitor)=0 ohms  Eq. (1)

The existence of such a short circuit condition in an active circuit cancause explosions or otherwise damage equipment, such as the powercontrol system 100 of FIG. 1. To avoid such a short circuit condition,the tuned reactor zig-zag transformer 500 can be tuned to 1.2 degreesoff a particular harmonic frequency.

Furthermore, the tuned reactor zig-zag transformer 500 operates inconjunction with the power capacitors 114 to form a power holding tankcircuit. In operation, the power holding tank circuit is configured tosmooth out power variations by resisting power sags via the powercapacitors 114 and by resisting power surges via the tuned reactorzig-zag transformer 500

V. Controller

With additional reference to FIGS. 6A-6C, aspects of an examplecontroller 600 will be disclosed. The controller 600 may correspond tothe controller 106 of FIG. 1 and can be configured to measure powerfactor in a power distribution system and to act upon software to switchstages 104 on or off to provide power factor correction. In someembodiments, the controller 600 can be configured to monitor and operatea power control system 100 for a power distribution system having anyvoltage configuration between about 90 volts and 600 volts.

As shown in FIG. 6A, the controller 600 includes a user interface 602comprising output means 604 and input means 606. The controller 600further includes a case strap 608 configured to couple the controller600 to ground 610, a multi-pin port 612 configured to send and receivedata to and from a remote node, a plurality of probe feeds 614, 616configured to measure various electrical parameters of a powerdistribution system, a reference voltage 618, and one or more controllines 620, 622, 624. Further, in some embodiments the controller 600 maybe configured to receive 110-volt power from a step down transformer 626coupled to a 480-volt power source.

The output means 604 can include one or more of a digital display 604Aand/or stage indicator lights 604B. The digital display 604A may beconfigured to display electrical data for a power distribution system inwhich the power control system 100 of FIG. 1 is implemented. Theelectrical data may include, for instance, power factor error as cosinetheta, voltage, total current being consumed, active calculated power(in watts), total reactive power (in watts), kVAr ratings output, stagecapacitor ratings for each of stages 104, and frequency of the multiplephase power signal, and the like or any combination thereof.

In some embodiments, the output means 604 include up to twelve stageindicator lights 604B, one each corresponding to one of twelve stages104 in the power control system 100 of FIG. 1, for instance. Alternatelyor additionally, there may be more or less than twelve stage indicatorlights 604B. Alternately or additionally, there may be more stageindicator lights 604B than stages 104 in the power control system 100 ofFIG. 1. In some embodiments, the controller 600 is configured to trackwhich stages are in use at any given time and to display which of thestages are in use via stage indicator lights 604B. Alternately oradditionally, the controller 600 can be configured to identify anystages 104 that include one or more failed components in order to avoidswitching the failed stage on and damaging the power control system 100or a user.

The input means 606 may include stage selectors 606A and rotary switches606B. The stage selectors 606A can be used to select a particular one ofthe stage indicators 604B corresponding to a particular stage 104 of thepower control system 100 of FIG. 1, for example. When a particular stageindicator 604B has been selected using stage selectors 606A, the digitaldisplay 604A may display certain electrical parameters for thecorresponding stage 104. Alternately or additionally, when a particularstage indicator 604B has been selected, the rotary switches 606B can beused to program certain actions, such as a timed delay for a particularstage.

Alternately or additionally, a user can use one or more of input means606 to set a particular power factor target or preset thermal dynamicsfor the power control system 100 if FIG. 1. Alternately or additionally,a user can use input means 606 to program the controller 600 to ignoreand not use one or more of stages 104.

The multi-pin port 612 can be configured to send data collected and/orgenerated by the controller 106 to a remote node, such as a computer ortelephone. Alternately or additionally, the multi-pin port 612 can beconfigured to receive instructions from the remote node. In someembodiments, the multi-pin port 612 implements two-wire telephonetelemetry, nine-pin computer contact methods, FireWire interface, and/orstandard fiber optics methods for communicating with the remote node.

The probe feeds 614, 616 are configured to measure various electricalparameters for a power distribution system in which the controller 600is implemented. For instance, the probe feed 614 can be configured tomeasure the current of a multiple phase power signal; in someembodiments, probe feed 614 can be coupled to a single one of theprimary busbars 102 of FIG. 1. In some embodiments, the probe feed 614comprises a current transformer probe feed. Alternately or additionally,probe feeds 616 can be configured to measure the voltage of each phaseof the multiple phase power signal and can be coupled one each to adifferent one of the primary busbars 102 of FIG. 1. Although not shown,the controller 600 can alternately or additionally receive temperaturedata for the controller 600 and/or power control system 100.

The control lines 620-624 can be configured to send control signals thatoperate the power control system 100 of FIG. 1. For instance, controlline 620 can be coupled to a fan or other active cooling system to allowthe controller 600 to turn the fan or other active cooling system on oroff for cooling the power control system 100. The controller 600 mayturn on the fan, for example, if received temperature data indicatesthat the controller 600 or power control system 100 is operating abovethe preset thermal dynamics set by the user.

Alternately or additionally, control line 622 may comprise one or morestage-specific control lines, each of the one or more stage-specificcontrol lines 622 coupled to a different one of stages 104 to allow thecontroller 600 to turn the stages 104 on or off for power factorcorrection.

Alternately or additionally, control line 624 can be coupled to an alarmcircuit in the controller 600 and an output device such that when thealarm circuit is activated, the controller 600 can communicate certainparameters to a user through the output device. For instance, thecontroller 600 can be configured to track the temperature of the powercontrol system 100 and if the temperature ever exceeds a particularvalue, the alarm circuit can be triggered to send an alarm to the user.

With additional reference to FIGS. 6B and 6C, the controller 600 canadditionally include a data compiler 628, output reader 630, compositeletter generator 632, processor 634, decision switch 636, stagedestination switch 638, and second destination switch 640. As shown inFIG. 6C, the controller 600 further includes a command module 642coupled to the processor 634, an execution switch 644 coupled to thecomposite letter generator 632, a time set delay switch 646, anoperation counter 648, a frequency counter 650, a capacitor efficiencymonitor 652, and a non-volatile memory chip 654. The time set delayswitch 646 is coupled to the data compiler 628 and the memory chip 656is coupled to the processor 634.

As best explained with reference to FIG. 6B, the data compiler 628 canbe configured to translate source code stored in memory chip 654 and/orreceived from a user or remote node via command module 642 into objectcode executable by the processor 634. In this example, the out putreader 630 can be configured to receive the object code and forward itto the processor 634. The object code executed by the processor 634 canresult in the processor 634 instructing the composite letter generator632 to generate one or more alphanumeric values for display on thedigital screen 604A.

Alternately or additionally, the data compiler 628 can be configured tocollect data from the power distribution system. The output reader 630can be configured to receive the data collected by the data compiler 628and to identify some or all of the collected data to display on thedigital screen 604A. The composite letter generator 632 can beconfigured to receive the data identified for display and to generateone or more alphanumeric values for display on the digital screen 604Athat are representative of the data received from the output reader 630.

In some embodiments, execution of the object codes causes the processor634 to send signals to the decision switch circuit 636, which analyzesthe signal to determine whether the signals are intended for one or moreof the stages 104 of FIG. 1 via stage destination switch 638, or areintended for one or more other destinations via second destinationswitch 640. For instance, the signal received from the processor 634 maycomprise a signal to switch one of stages 104 on or off. Alternately oradditionally, the signal received from the processor 634 may comprise asignal to switch the fan or other active cooling system on or off, or asignal to turn an alarm on or off, or a signal to display certain dataon the digital display 604A.

If the signal received from the processor 634 is intended for one ormore of the stages 104 of FIG. 1, decision switch 636 forwards thesignal to stage destination switch 638, which identifies the intendeddestination stage and forwards the signal to the intended destinationstage. In this example, the signal may be configured to either switchthe destination switch on or off. If the signal received from theprocessor 634 is intended for one or more other destinations, thedecision switch 636 forwards the signal to second destination switch640, which identifies the intended destination (e.g., fan, alarm,digital display) and forwards the signal to the intended destination.

As best explained with reference to FIG. 6C, the command module 642 isconfigured to allow a user to access data stored on memory chip 654and/or received from data probes in the power distribution system.Alternately or additionally, the command module 642 can be configured toreceive user input in programming certain parameters of the controller600, such as a target power factor, a timed delay for switching stages,a target operating temperature, exclusion of one or more of stages 104,or the like or any combination thereof. Such programming instructionscan be stored in memory chip 654 and/or can be executed by executionswitch 644. Time set delay switch 646 can be configured to implement atimed delay for switching stages.

Frequency counter 650 can be configured to count the AC frequency of themultiple phase power signal. Operation counter 648 can be configured tocount one or more parameters, such as the number of times that each ofstages 104 of FIG. 1 is switched on, switched off, or both. In someembodiments, the operation counter 648 can count up to 10 million.Capacitor efficiency monitor 652 can be configured to track capacitorvalues for the power capacitors 114, 120 of FIG. 1, for example. Thedata generated by frequency counter 650, operation counter 648, andcapacitor efficiency monitor 652 may include AC frequency of themultiple phase power signal, switching count per stage, and/or capacitorproficiency. This data can be stored in memory chip 654 and/or reportedto a user via digital display 604A and/or multi-pin port 612, forexample.

The memory chip 654 can comprise electrically erasable programmableread-only memory (“EEPROM”) in some embodiments. Alternately oradditionally, the memory chip 654 can comprise other non-volatile orvolatile memory. Alternately or additionally, the controller 600 caninclude a separate volatile memory chip in addition to the memory chip654. In some embodiments, the memory chip 654 can be configured to storedata collected from the power distribution system, and/or data generatedby performing calculations using the collected data. Alternately oradditionally, the memory chip 654 can be configured to store targetvalues, such as target operating temperature and/or target power factor,as well as other parameters.

In some embodiments of the invention, operations such as stage switchingcan be performed automatically by the controller 600 when relevantconditions are detected by the controller 600. Alternately oradditionally, the controller 600 may include a manual override allowinga user to determine when to perform operations that are normallyperformed automatically by the controller 600.

VI. Active Harmonic Filter

With additional reference to FIGS. 7A and 7B, aspects of an exampleactive harmonic filter 700 will be disclosed that can be implemented inconjunction with the power control system 100 of FIG. 1, or in otherenvironments. The active harmonic filter 700 can be controlled as astage by, e.g., the controller 106 or 600 of FIG. 1 or 6, for example.Further the active harmonic filter 700 can be coupled in series to theprimary busbars 102 of FIG. 1, for instance.

As shown in FIG. 7A, the active harmonic filter 700 includes a frequencyrange circuit gate 702, and one or more harmonic frequency destroyingcircuits 704A up to 704N. In some embodiments, the active harmonicfilter 700 is configured to be coupled to a direct current (“DC”) powersupply 706 to supply DC power to one or more components of the activeharmonic filer 700. The DC power may comprise 50 volts DC in someembodiments.

Alternately or additionally, the active harmonic filter 700 can beconfigured to destroy 25 amps of harmonic power. Alternately oradditionally, a plurality of harmonic filters can be stacked to mitigateharmonics that are more powerful than 25 amps.

In some embodiments, the active harmonic filter 700 is not to beconstrued to be operated as a multi-level notch filter. Each ofdestroying circuits 704A-704N can be a multi-bandwidth system that doesnot involve notch filtration in any way. As will be explained below, ifa harmonic anomaly is small, the mitigation provided by the activeharmonic filter 700 will also be small and in perfect imitation of theharmonic sent against itself.

Although the active harmonic filter 700 will be discussed in the contextof a 3-phase system approximating 480 volts, embodiments of theinvention are not limited to 3-phase systems approximating 480 volts.For instance, the active harmonic filter 700 can be configured to handlemore or less than 480 volts and/or in can be configured to operate insingle phase mode, as will be appreciated by those skilled in the artwith the benefit of the present disclosure.

In some embodiments of the invention, each of the one or more destroyingcircuits 704A-704N can be configured to substantially eliminate aparticular harmonic frequency in the 60 Hz-100 kHz range. As such, theexact number of destroying circuits 704A-704N can depend on theparticular harmonic frequencies present in a power distribution system.For instance, a power distribution system for a single-family dwellingis likely to have fewer problematic harmonic frequencies in the 60Hz-100 kHz range than the power distribution system for a multi-storyoffice dwelling. Thus, in some embodiments, the active harmonic filer700 can be built after first identifying the harmonic frequency(ies)present in the corresponding power distribution system.

Some power distribution systems may require an active harmonic filter700 with as many as fourteen destroying circuits 704A-704N tosubstantially eliminate up to 14 problematic harmonic frequencies in the60 Hz-100 kHz range. Alternately, other power distributions systems maynot require an active harmonic filter 700 at all. Alternately, otherpower distribution systems may require an active harmonic filter 700with as few as one destroying circuit to substantially eliminate as fewas one problematic harmonic frequency.

The frequency range circuit gate 702 is configured to be coupled to theprimary busbars 102 of FIG. 1 and to identify particular harmonics inthe multiple phase power signal carried by the primary busbars 102. Uponidentifying a particular harmonic, the frequency range circuit 702 feedsthe power signal to the appropriate destroying circuit 704A-704N.

Each destroying circuit 704A-704N is configured to substantiallyeliminate harmonic frequencies within a particular harmonic frequencydomain centered around a particular problematic harmonic frequency. Theharmonic frequency domains can be configured to slightly overlap eachother by three distinct frequencies beyond each domain.

One example embodiment of a destroying circuit 750 for a prime harmonicis disclosed in FIG. 7B. The destroying circuit 750 includes a counter752, a time delay 754, a logic circuit 756, and a sine wave creator 758.In some embodiments, the prime frequency of the multiple phase powersignal may be at or around 60 Hz for North America, 50 Hz for the UK, or400 Hz in the aerospace field. However, the nominal prime frequency isnot always the true prime frequency. Accordingly, the zero counter 752can be configured to determine a prime frequency of the multiple phasepower signal by counting zeros in the power signal. Assuming the powersignal is sinusoidal, the true prime frequency can be determined bycounting three successive zero voltage levels and comparing against aninternal clock.

In the example of FIG. 7B, the time delay 754 is configured to delay thepower signal by ¼ phase to create an out-of-phase signal. Further, thelogic circuit 756 is configured to lock to the sine wave creator 758 andthe sine wave creator 758 can be configured to imitate the true primefrequency. The logic circuit 756 can be configured to compare the ¼out-of-phase power signal to the created sinewave. If the two signalsare equal, the logic circuit 757 is configured to allow the ¼out-of-phase power signal to pass through the destroying circuit 750unchanged. If the ¼ out-of-phase power signal is different from thecreated sinewave, the logic circuit 756 can be configured to feed the ¼out-of-phase power signal back against the actual power signal todestroy the harmonic frequency.

Although the active harmonic filter 700 has been described as beingcoupled in series to the power distribution system, the active harmonicfilter 700 can alternately be coupled to the power distribution systemin parallel. In this embodiment, there is no differential between Deltaor Wye connected three phase power. However, mitigation efficiency canbe optimized if the location of the source of the harmonic frequency isknown. In this case, the active harmonic filter can be coupled to thepower distribution system proximate the source of the harmonicfrequency.

Further, in some embodiments, the active harmonic filter 700 remains atrest and is not engaged if the logic circuit 757 does not detect anyharmonic outside of the prime. Therefore each of up to fourteen domainscan operate independently of each other and can be driven only whencalled for.

The embodiments described herein may include the use of a specialpurpose or general-purpose computer including various computer hardwareor software modules, as discussed in greater detail below.

Embodiments within the scope of the present invention also includecomputer-readable media for carrying or having computer-executableinstructions or data structures stored thereon. Such computer-readablemedia can be any available media that can be accessed by a generalpurpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium which can be used to carryor store desired program code means in the form of computer-executableinstructions or data structures and which can be accessed by a generalpurpose or special purpose computer. When information is transferred orprovided over a network or another communications connection (eitherhardwired, wireless, or a combination of hardwired or wireless) to acomputer, the computer properly views the connection as acomputer-readable medium. Thus, any such connection is properly termed acomputer-readable medium. Combinations of the above should also beincluded within the scope of computer-readable media.

Computer-executable instructions comprise, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing device to perform a certain function orgroup of functions. Although the subject matter has been described inlanguage specific to structural features and/or methodological acts, itis to be understood that the subject matter defined in the appendedclaims is not necessarily limited to the specific features or actsdescribed above. Rather, the specific features and acts described aboveare disclosed as example forms of implementing the claims.

As used herein, the term “module” or “component” can refer to softwareobjects or routines that execute on the computing system. The differentcomponents, modules, engines, and services described herein may beimplemented as objects or processes that execute on the computing system(e.g., as separate threads). While the system and methods describedherein are preferably implemented in software, implementations inhardware or a combination of software and hardware are also possible andcontemplated. In this description, a “computing entity” may be anycomputing system as previously defined herein, or any module orcombination of modulates running on a computing system.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed is:
 1. A power control system, comprising: one or morestages, each of the one or more stages configured to generate a leadcurrent when coupled in parallel to a power distribution system, atleast one of the one or more stages comprising a notch filter and apower tank circuit; a plurality of primary busbars operatively coupledto each of the one or more stages, each of the plurality of primarybusbars configured to carry one phase of a multiple phase power signal;and a controller operatively coupled to each of the one or more stagesand configured to: determine when to switch each of the one or morestages on and off; count a number of times each stage is switched on;and track one or more electrical parameters of the power distributionsystem, power control system, or both.
 2. The power control system ofclaim 1, wherein each of the one or more stages comprises: a multiplephase circuit breaker coupled to the plurality of primary busbars; oneor more power capacitors configured to create the lead current when thestage is turned on; and a capacitor switching contactor coupled betweenthe multiple phase circuit breaker and the one or more capacitors. 3.The power control system of claim 2, wherein the one or more powercapacitors comprise a plurality of power capacitors arranged inparallel, and wherein each of the one or more stages further comprise aplurality of secondary busbars coupling the power capacitors to eachother in parallel.
 4. The power control system of claim 2, wherein thecapacitor switching contactor comprises: a plurality of contact pointsets configured to open and close electrical connections between theplurality of primary busbars and the stage in which the capacitorswitching contactor is implemented; a plurality of arc chutes, each arcchute positioned proximate a contact point set to receive electricaldischarge current caused when the contact point set opens an electricalconnection; a solenoid mechanically coupled to one contact point of eachcontact point set and configured to impart forces sufficient to open andclose the electrical connection to the one contact point; and aninsulating enclosure configured to form an electromagnetic interferenceshield around the plurality of contact point sets, the plurality of arcchutes, and the solenoid.
 5. The power control system of claim 4,wherein the insulating enclosure comprises plastic with Aluminum threadembedded therein to form the electromagnetic interference shield.
 6. Thepower control system of claim 2, wherein the at least one of the one ormore stages further comprises a tuned reactor zig-zag transformer, theone or more power capacitors and the tuned reactor zig-zag transformerof the at least one of the one or more stages forming the notch filterand power tank circuit.
 7. The power control system of claim 6, whereinthe tuned reactor zig-zag transformer comprises an iron core largeenough to prevent magnetic saturation.
 8. The power control system ofclaim 7, wherein the tuned reactor zig-zag transformer weighs about 70pounds.
 9. A power capacitor, comprising: three balanced capacitorsarranged in a delta configuration, the delta configuration includingthree contact points interposed between the three balanced capacitors;three resistors, each resistor including two inputs and one output, eachinput begin coupled to one of the three contact points; and three diodesconfigured to allow power stored in the balanced capacitors to bedischarged, each diode including an input coupled to an output of acenter tap resistor and a grounded output.
 10. The power capacitor ofclaim 9, further comprising a steel enclosure forming a cavity in whichthe three balanced capacitors, three resistors, and three diodes aredisposed.
 11. The power capacitor of claim 10, further comprisingdielectric oil substantially filling volume in the cavity not occupiedby the three balanced capacitors, three resistors, and three diodes, thedielectric oil being substantially non-flammable.
 12. The powercapacitor of claim 10, wherein the dielectric oil comprises FR3dielectric oil.
 13. The power capacitor of claim 9, wherein the powercapacitor is rated for 10 kVArs to 25 kVArs.
 14. The power capacitor ofclaim 9, wherein each of the three balanced capacitors is configured torepair itself if damaged.
 15. The power capacitor of claim 14, whereineach of the three balanced capacitors comprises a plurality of layersincluding a foil layer, an insulating layer; and a repairing layerdisposed between the foil layer and the insulating layer, the repairinglayer configured to repair the balanced capacitor in the event ofdamage.
 16. The power capacitor of claim 15, wherein the insulatinglayer comprises Mylar.
 17. The power capacitor of claim 14, wherein therepairing layer comprises a thermo plastic configured to melt atapproximately 400° C.